The full-on Zoolander experience

Body paint and prosthetic noses, huge mittens and Slade haircuts ... Fashion show novice Alexis Petridis gets to grips with the autumn menswear collections, to find out if it's all just bonkers outfits

A model at the 2007 Pianegonda presentation in Milan. Photograph: Giuseppe Cacace/Getty Images

It is a damp Monday evening in the middle of the Milan menswear shows and I do not have an invite for Prada. I am thus barred from entry, and relegated to the heaving scrum of similarly uninvited people on the pavement of Via Fogazzaro. If I crane my neck, I can occasionally catch a glimpse past the Prada-suited heavies on the door - say what you like about the menswear shows, they have the best-dressed bouncers in the world - and into the lobby. I can see people with expensive-looking complimentary drinks and canapes. More disheartening still, I can see the Guardian's deputy fashion editor talking frantically into her mobile, apparently on my behalf and apparently to no avail.

Outside, people with whom I was at least on nodding acquaintance earlier in the week sweep past. They could avert their eyes no more studiously if I were carrying a clipboard and wearing a hopeful grin and a fluorescent orange tabard with "Age Concern" written on it. If being stuck outside one of the big shows without an invite isn't exactly social death, it certainly gives you an inkling of how a charity mugger must feel as they go about their noisome business. There are moments when the entire world appears to be sweeping past me: excitable Japanese women, American fashion journalists bellowing camp badinage at each other, surly Russians. Dylan Jones, GQ's suave British editor, stops long enough to express heartfelt sympathy for my predicament by laughing at me. At one point, the scrum parts respectfully to allow Anna Piaggi, Italian Vogue's most iconic contributor, to pass unmolested. Piaggi is a lady of indeterminate but advanced age, wearing Child Catcher make-up, pink hair dye and what seems to be a very, very small metal hat.

It's not a lot of fun out here, being drizzled on and pushed about, but nor is it an entirely unexpected state of affairs. In fact, as a fashion neophyte, here to give an ingenu's eye-view of the autumn/winter 07 menswear shows - a week in Milan, followed by a week in Paris - I'd go so far as to say it's exactly what I expected. However little we may claim to know or care about the world of fashion, however arcane and bewildering we find talk of venting and applique and must-have items, we all think we know what designers' runway shows are like. We've seen Pret-a-Porter, Ugly Betty and The Devil Wears Prada, and umpteen documentaries on the subject. We know they exist in an unforgiving, venal, tantrum-prone parallel universe of size zero body fascism and snobbishness and dressing with impunity in a manner that would get you laughed at in Tesco, a world in which mere mortals should expect to be ignored and excluded and, indeed, shoved out of the way by a pensioner with pink hair and a very small metal hat.

But everyone I speak to in Milan and Paris - from stylists to photographers to seasoned fashion hacks - is keen to point out that the popular image of the catwalk show is based entirely around womenswear. I am reliably informed that it is only when the frocks come out that the real nuttiness starts. It's at womenswear shows that the real sniping takes place, where proceedings are delayed for hours because a solitary celebrity is late and doctors have to be called to sedate middle-aged journalists driven to conniptions because their seat is in a less exalted place than that of a rival.

There's plenty of money sloshing around menswear: indeed, a spectacularly paranoid rumour circulates that at least one fashion house secretly trains cameras on the audience at their show, and ruthlessly pulls their advertising from any publication whose journalists are deemed to be displaying insufficient enthusiasm. But the fact remains that women's clothes are simply much bigger business and higher profile than those of their male counterparts.

Stories of CCTV-wielding designers aside, menswear is apparently a laid-back world of sunny smiles, camaraderie and fathomless bonhomie by contrast with its distaff cousin. Celebrities are thin on the ground. The footballers and actors and musicians who might wear the clothes on offer chose to express their allegiance to designers by flocking to the womenswear shows instead: seemingly less interested in watching male models strut their stuff than the female variety.

The only show that attracts big names proves to be Dior Homme, where Hedi Slimane's cutting-edge reputation pulls David Furnish, Karl Lagerfeld, the Pet Shop Boys, Janet Street-Porter and, perhaps more surprisingly, Lulu. The latter looks on, boggling, as Slimane's models - picked not from agencies but from the dance floors of indie clubs - stomp about in Doc Marten-like boots and spiky hair, with the cuffs of their mohair jumpers sticking out from under their crombies and the crotches of their trousers dangling unaccountably around their knees. Maybe she's surprised that - the dangly crotch situation notwithstanding - fashion's cutting edge currently involves looking like a member of the audience at a 1984 Echo And The Bunnymen gig.

Meanwhile, my experience outside Prada is as close as I get to Ugly Betty territory in the whole fortnight, and even that ends shortly after the arrival of Piaggi, with an apologetic and polite Prada press officer letting me in. Once indoors on the Styrofoam seating, I find myself surprisingly thrilled by the clothes that come weaving around the maze-like catwalk. Like most men, I could happily live the rest of my life without wearing a pair of trousers made from angora wool, and the attempt to reclaim the bum bag as a chic accessory seems a bit hopeful, but there are beautifully cut hooded coats and dip-dyed jackets that fade from dark grey to green. I mention my enthusiasm to the girl next to me. She agrees: "Look at us!" she squeaks enthusiastically, "bonding over Prada!" I smile and nod, but the phrase strikes fear into my heart. Perhaps I've been sucked into the world of fashion without realising it. Perhaps this is the thin end of the wedge. One minute you're bonding over Prada, the next thing you know, you're turning up at parents' evening with your crotch flapping in the breeze and a very, very small metal hat. Or perhaps not. However seduced you are by the collections, you could never confuse the menswear shows with the real world. This much becomes clear within minutes of my arrival in Milan, when I find myself at Burberry's show, watching a man wearing an enormous pair of fake fur mittens walking up and down a runway to the deafening strains of the Boomtown Rats' 1979 follow-up to I Don't Like Mondays, Diamond Smiles, a song so dimly remembered that mention of it would probably cause Bob Geldof himself to scratch his head and beg your pardon.

In fact, the mittens turn out to be something of a red herring. As the fortnight goes on, it becomes apparent that designers have a habit of throwing one or two insane items of clothing into an otherwise straightforward collection. They seem to be there in an attempt to underline the designer's commitment to envelope-pushing. A similar function is performed by the explanatory notes they leave on your seat, which explain nothing other than that someone in the designer's employ has been on an exhaustive but successful search for Europe's most pretentious writer.

Most of what's happening on the Burberry runway is conservative: lots of grey and taupe, military coats, some nice knitwear. Anyone tending to nod off during an otherwise unremarkable Louis Vuitton show is momentarily galvanised by the appearance of some shoes made from pink velvet and some trainers with vastly distended turned-up toes, the latter ideal for anyone planning on taking part in the London Marathon dressed as a clown.

The suits and black tie gear offered by ultra-high-end designers Bottega Veneta are enlived by some stomach-churning explanatory notes: there's something about the words "reversed lambskin" and "perforated goatskin" that makes you think of things dying by the side of country roads with a tyre track on their head and their innards hanging out.

More military coats at Versace might look a little tired, but the accompanying guff could knock you sideways: "Versace Man rediscovers the power of discipline... Though the closest to actual war Versace Man will get is an amorous conflict, he wears the badge of gallantry with a contemporary edge." At one stage, Versace Man's badge of gallantry with a contemporary edge takes the form of a two-tone black-and-white bow tie, like something a member of Madness might have worn in the video for Baggy Trousers. One is thus diverted during longueurs on the catwalk by the entertaining mental image of Versace Man flying through the air while playing a toy saxophone.

And even when the clothes look reassuringly normal, there are the models to contend with. Admittedly, male models look less like they arrived in a veal crate than their female counterparts, but there's no getting around the fact that they're incredibly young - you can occasionally see acne beneath the foundation - and that the clothes they're wearing are intended for people far older. There's something inescapably odd about watching teenagers parading around in clothes no teenager could afford, or indeed would want to wear: what self-respecting 17-year-old would abandon his hoodie and studded belt in favour of a luxurious silk dressing gown and bow tie? You occasionally wonder whether the blank expression they all wear might hide something else: embarrassment or anger. Either way, it makes for slightly discomfiting viewing.

As does the audience. There are peculiar sights that soon become comforting because you see them at every show, including a contingent of studious Japanese journalists who never remove their sunglasses - given the stygian gloom in which most of the shows take place, you do start to wonder about the veracity of the reports they're getting in Tokyo - and the bizarre hairstyle of the Herald Tribune's redoubtable fashion editor Suzy Menkes, featuring a quiff so elaborate, it acts like a sort of equerry, entering the room several minutes before she does and announcing her imminent arrival.

But equally, there are sights on offer to which you never quite become accustomed. Chief among these are the representatives of the press. At risk of sounding a little Al Murray, it behoves me to note that most of the Britons dress in a style that's mercifully tasteful. Not so our continental brethren. They look completely nuts. There is a middle-aged man with Michael Heseltine's hair, Craig David's beard and a floor-length leopard-skin jacket. There is a portly man with a shaved head who has teamed a poncho with a pair of silver leggings. There is a man wearing a baseball cap the wrong way round, which would be unremarkable in itself were it not for the fact that the baseball cap has a length of fabric attached to the back of it, designed to keep the sun off your neck, which is now obscuring his face. These, you must keep reminding yourself, are people entrusted with the job of telling the rest of us how to dress ourselves.

The real fun comes when the nutters in the audience find themselves upstaged by what's happening on the catwalk. It happens at Alexander McQueen's show, a wildly enjoyable, largely unwearable riot of enormous trousers, electric-blue beanie hats, shoulder pads, suits encased in plastic and wigs apparently modelled on the village-idiot haircut sported in the 70s by Slade guitarist Dave Hill. But even McQueen is left looking like the Next catalogue by John Galliano's show. It is what you might call the full-on Zoolander experience. Body paint is involved, as are prosthetic noses. Tights are worn over the face. There are vast headdresses festooned with giant fabric penises. It is utterly ridiculous and quite spectacularly entertaining - a genuine show. In addition, if you ignore the outlandish styling, the clothes at its centre are strangely prosaic: underwear and T-shirts branded with the Galliano logo.

Admittedly, the styling is hard to ignore when it involves huge metal helmets (one in the shape of a Cyberman) on top of one another. Nevertheless, it sums up the sleight of hand at the heart of the menswear shows. Most of the clothes shown in Milan and Paris will never go on sale. Those that do will sell in minuscule quantities. What really matters to the designers, where they really make their money from men, is in shifting accessories - bags and belts and luggage - or branded cologne. You could argue that menswear shows are the most expensive perfume adverts you'll ever see.

Strangely, it is not McQueen or Galliano that brings home the sheer strangeness of the fashion world. It's Emporio Armani. The show takes place in a vast purpose-built concrete building on the outskirts of Milan. The explicatory notes are disappointingly sane and the most outlandish thing the show features are some oversized boots: the real focus is on Armani's new range of snowboarding clothes. Yet the reaction of the audience is unlike anything else I see during the menswear shows. For the first and only time, people applaud not just at the end of the show, but during it. I find myself joining in. And, as I clap, I'm hit by a sudden revelation. Outside the Armani building, it's an ordinary weekday afternoon in January. Babies are being born. Life‑support machines are being turned off. People are going to the supermarket. I, on the other hand, am sat in a kind of giant concrete lecture hall, rapturously applauding - for reasons that are not entirely clear to me - a pair of snowboarding trousers. The weird world of men's fashion has never seemed weirder.